Instantaneous acting voltage sensitive tube



Aug. 7, 1956 P. BIANCHI INSTANTANEOUS ACTING VOLTAGE SENSITIVE TUBE Filed June 23, 1952 INVENTOR RENATO BIANCHI ATTORNEYS United States Patent Ofiiice 2,758,252 Patented Aug. 7, 1956 2,758,252 INSTANTANEOUS ACI'INC;1 VOLTAGE SENSITIVE TUB Renato Bianchi, Laurel, Md. Application June 23, 1952, Serial No. 295,130 3 (Ilaims. (Cl. 315-233) (Granted under Title 35, U. S. Code (1952), sec..266)

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to a cold vice and more particularly to an instantaneous conducting voltage regulating tube for use with suitable circuits such, for example, as those employed in an electric fuzeor the like.

The present invention contemplates the provision of a new and improved cold cathode discharge tube having the desired requirements and essential characteristics for use in electric fuze arrangements employed by the armed ing at least two electrodes bridged or connected by a minute wire adapted to be fused upon application of a predetermined voltage applied thereto by way of an' external connection to one of the bridged electrodes thereby providing a source of ionization to initiate gaseous conduction of the tube at the instant the wire and the wire connection is broken.

Heretofore, prior art devices have not proven entirely satisfactory for the reason that the radioactive material used on or near the electrodes for obtaining instantaneous operation of such devices adversely affected the physical condition of the personnel during the construction of such devices. Furthermore, due to the high cost of the radioactive material employed and the additional cost in medical aid administered to those affected by the radioactive material and the loss of their prior devices is high.

The present invention contemplates the provision of a new and improved discharge tube which overcomes the disadvantages heretofore found in prior art devices and in which means are provided for rendering the tube conductive thereby to charge suitable energy storage means until the voltage thereon has risen such that the voltage differential between tube electrodes is insufiicient to maintain tube conduction whereupon the tube is extinguished and the storage means is thus effectively discon nected from the source of charging voltage.

An object of the invention is to provide a new and improved instantaneous conducting voltage regulating tube for use in an electric fuze.

Another object of the invention is to provide a new and improved cold cathode diode wherein instantaneous operation thereof is achieved in response to an initial impulse received thereby.

Another object is the provision of a new and improved cold cathode tube wherein a cathode bridge wire is fused in response to an initial impulse received thereby whereupon the tube is rendered thereafter conductive by gaseous discharge. Still another object is-the provision of 'a cold cathode cathode discharge deat a predetermined pressure. The

is fused services, the cost of these tube in which means fused by an initial impulse received thereby provides a source of ionization sufiicient to initiate gaseous conduction of the tube.

A still further object is the provision of a voltage regulating tube in which an initial impulse renders the tube conductive thereby to energize at least one circuit means connected thereto and charge at least one storage device and in which the circuit means and storage devices are isolated therefrom after conduction of the tube has ceased;

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein:

Fig. l is a central longitudinal sectional view, of the device of the present invention and a circuit suitable for,

use therewith according to a preferred embodimant thereof;

Fig. 2 is a view similar to Fig. 1 showing an alternative arrangement of the tube elements and circuits therefor; and,

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2.

Referring now to the drawing wherein like reference I characters designate like parts through the several views and more particularly to Fig. 1 the numeralltl generally indicates the voltage regulating cold cathodev discharge tube of the present invention which comprises an envelope 11 composed of any material suitable for the purpose such, for example, as glass or the like, the envelopebeing filled with a suitable ionizable gas at a predetermined pressure.

The envelope is provided with a supporting structure 12 having secured therein in spaced relation with respect to each other a pair of electrodes 13 and 14, one terminal end of each electrode extending a predetermined amount into the envelope 11, the other terminal end of each electrode extending through the supporting structure 12 and a predetermined amount therebeyond.

Secured to the extremity of each of the electrodes 13 and 14 as at 15 and 16 is a fusible bridge member 17, the

bridge member being formed of a fine fusible wire strand composed of any material suitable for the purpose such,

for example, as Nichrome o-r'the like drawn and etched. to the desired size. The electrode 13 is connected by con-s example, is applied to conductor 18, condenser C1 starts to charge over the charging circuit just described andincluding bridge wire 17. This charging current is of such high value that the bridge wire is fused while the condenser is receiving a fractional part of the full voltage. It may be assumed, for example, that the wire is fused when the condenser has charged to a potential of 25 volts. When this occurs, the gas in tube 10 is ionized and therefore remains conductive despite the break in the bridge wire caused by fusing thereof and the voltage and charge of the condenser C1 continue to build up.

When the voltage on condenser C1 has risen to a value such that the voltage differential between electrodes 13' and 14 is no longer sufficient to maintain tube conduction,

the tube is extinguished and condenser C1 is thus effectively disconnected from the source of charging voltage. The

charge now remaining on condenser Crcorresponds to a"- voltage of slightly less than the voltage applied to conductor 18 and in the order of approximately volts, in

synapse 1-3 the example assumed. The final or maximum value of the voltage on condenser C1, it will be understood, is a function of the voltage applied to conductor 18 and the extinguishing potential of the tube.

It will be understood, however, that the charge remaining on condenser C1 may be employed to fire a low energy detonator or primer arranged within an electrical fuse in a projectile as the condenser is discharged upon impact of the projectile with a target or when the projectile has aproached within close proximity of the target, as the case may be.

It will be further understood, that two or more of the aforesaid tubes of Figs. 1 or 2 or any combination thereof having ditferent extinguishing potentials may be arranged in parallel and a voltage impulse applied thereto, the bridge wire in each tube will be fused and only those tubes which have extinguishing potentials lower than the voltage differential of the tube electrodes will remain conductive. Also, if desired, the tubes may be extinguished in predetermined timed sequence by employing suitable resistance elements in the charging circuits of the condenser loads.

Referring now to Fig. 2 the envelope 11 is provided with a plurality of mutually spaced electrodes 23, 24 and 25 sealed in the support 12, the electrode 23 being a control electrode, and the electrodes 24 and 25 being discharge electrodes. A bridge wire 25 is connected across electrode 23 and the discharge electrode 24. The control electrode 23 is connected by a conductor 27 to a source of electrical energy whereby an impulse may be applied selectively at will to electrode 23 by way of conductor 27. The electrodes 24 and 25 are connected by conductors 28 and 29 respectively to one terminal end of a pair of condensers C2 and C3 respectively, the other terminal of each condenser being grounded.

By this arrangement it will be understood that condensers C2 and C3 are charged by way of conductors 28 and 29. When the voltage on condensers C2-C3 has reached a predetermined value such that the voltage differential between electrode 23 and electrodes 24 and 25 is no longer sufficient to maintain tube conduction, the tube is extinguished and thus condensers C2-C3 are effectively disconnected from the source of charging voltage. The charge now remaining on each end of the condensers CzC3 corresponds to a voltage slightly less than the voltage applied to conductor 27. Furthermore, it will be understood that when a voltage is applied to conductor 27, condenser C2 starts to charge over the aforesaid charging circuit including the bridge wire 26. The initial charging current of condenser C2 is of such high value that the bridge wire is fused while condenser C2 is receiving a fractional part of the gas in full voltage over conductor 27. When this occurs the tube is ionized and rendered conductive and concurrently therewith condenser C3 starts to charge. It will be understood that the tube remains conductive despite the break in the bridge wire and thus the voltage and charge of condensers C2C3 continue to build up until the tube is extinguished.

Briefly, stated in summary, the present invention provides a new and improved voltage discharge tube void of harmful radioactive material and which comprises the desired characteristics of instantaneous breakdown, constant breakdown potential and constant extinguishing potential and control and output circuits therefor. Furthermore, the device provides a fine bridge wire which is fused in response to a voltage applied thereto, the fusing of the wire initiating gaseous conduction of the tube whereupon the tube will remain conductive until the voltage on the storage device or devices, as the case may be, has risen such that the voltage differential between the control and discharge electrodes is insufficient to maintain tube conduction and thus the tube is extinguished and the storage device or devices disconnected from the source of charging voltage.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced other than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a voltage regulating device, a cold cathode gas discharge tube comprising a sealed envelope containing an ionizable gaseous medium, a control electrode sealed to said envelope for receiving an electrical impulse from an external source of electrical energy, a pair of discharge electrodes sealed to said envelope in mutual spaced relation with said control electrode, a fusible bridge Wire secured to said control electrode and to one of said discharge electrodes, said bridge wire being fused in response to said impulse for providing a source of ionization of said gaseous medium sufiicient to render the tube conductive, means connected to said discharge electrodes for providing a pair of discharge paths therefrom as the bridge wire is fused and the tube is rendered conductive, said means including a pair of condensers connected respectively from said discharge electrodes to ground and charged while the tube is rendered conductive, said con densers being isolated from said control electrode and from each other when the condensers have been charged to such value that the voltage differential between said control and discharge electrodes is insuificient to maintain tube conduction.

2. In a voltage regulating device, a cold cathode gas discharge tube comprising a sealed envelope containing an ionizable gaseous medium, an impulse receiving electrode and a plurality of discharge electrodes, at fusible bridge Wire secured to said impulse receiving electrode and to one of said discharge electrodes, said bridge wire being fused in response to said impulse to provide a source of ionization of said medium sufficient to initiate gaseous conduction of the tube and concurrently therewith a plurality of gaseous discharge paths effective from said impulse receiving electrode to said discharge electrodes respectively, a plurality of condensers operatively connected between said discharge electrodes respectively and ground, said condensers being adapted to be charged to a predetermined value while the tube is rendered conductive and to be isolated from said impulse receiving electrode when the condensers have been charged to said predetermined value and the voltage differential between said impulse receiving electrode and discharge electrodes is insuflicient to maintain tube conduction.

3. In a voltage regulating device, a cold cathode gas discharge tube comprising a sealed envelope containing an ionizable medium, an impulse receiving electrode and a pair of discharge electrodes sealed to said envelope, a fusible member bridging said impulse receiving electrode and one of said discharge electrodes, said member being fused in response to said impulse to provide a source of ionization of said medium sufficient to initiate gaseous conduction of the tube, a pair of discharge paths respectively connected to said discharge electrodes, and a pair of condensers respectively connected in said discharge paths between said discharge electrodes and ground said condensers being charged to a predetermined value as the tube is rendered conductive, said condensers being isolated from said impulse receiving electrode when the condensers have been charged to said predetermined value and the voltage differential between said impulse receiving and discharge electrodes is insufficient to maintain tube conduction.

References Cited in the file of this patent UNITED STATES PATENTS 1,898,060 Noble Feb. 21, 1933 2,526,370 Kott Oct. 17, 1950 2,538,367 Kott Jan. 16, 1951 2,582,480 Dimond Jan. 15, 1952 

